Liquid dispensing apparatus



Aug. 9, 1932;

w. H. DE LANCEY LIQUID DISPENSING APPARATUS Filed Nov. '14, 1931 I INVENTOR. WARREN H. DE LANCEY.

BY Y

ATTORNEYS.

Patented Aug. 9 i 1932 UNITED STATES PATENT OFFICE WARREN H. DH TANC Y, OESBRINGFIELD, MASSACHUSETTS, ASSIGNOH To GILBER'J." a BARK R MANUFACTURING COMPANY, or WEST SPRINGFIELD, MASSACHUSETTS,

A CORPORATION or MASSACHUSETTS LIQ'IJ'IID DISPENSING APPARATUS Application filed. November 14, 1931. Serial NO. 575,084.

This invention relates to improvements in dispensing apparatus and particularly to the class of apparatus used for dispensing gasoline and the like.

The invention relates particularly to a dispensing system of a type which is normally closed. A common example of this type of system is found in the so-called meter pump. A power-operated pump draws liquid from a storage tank through a suction pi e, having a check valve therein. The pump orces such liquid through a delivery conduit, in which a meter is interposed and which includes 'a 1 flexible hose terminating with a valved nozzle. The valve in the hose nozzle is normally closed and the hose, the delivery conduit,

and the suction pipe as far back as the check valve, are maintained full of liquid under pressure. It is common practice to provide in such a system a by-pass from the delivery conduit to the suction pipe and to control such by-pass by a relief valve, which opens after a predetermined pressure has been built up in the delivery conduit. This bypass is supposed to guard against the building up of excessive pressures in the delivery conduit. It does not, however, accomplish its purpose satisfactorily in all cases and the reason is that liquid cannot escape from the suction pipe into the storage tank because of the closed check valve therein. Such check valve is a necessary element and cannot. be dispensed with. As a consequence of the arrangement described, it is possible for excessive and dangerous pressures to build up in the closed dispensing system. If the apparatus is used only infrequently on a very hotday, the expansion of the liquid in the closed system will create a dangerous pressure, which cannot be relieved by the customary relief valve located and arranged as described. lnstances have been found where the pressure has been built up to such an extent that the flexible hose cannot readily be (V bent. Such abnormal pressures, particular- 1y in the flexible hose, create a rear hazard which needs to be overcome. It is also possible to build up a high pressure in the closed 50 system by a liquid hammer amion caused by a sudden or snap closing of the hose nozzle valve.

The main object of the inventionis the provision of means for relieving suchexcess pressures in. a closed dispensing system of the class described. and the means chosen for this purpose consists of a chamher which is connected to the suction side of the pump. Each .time the pump is operated, the suctionis applied to this chamber as well as to the liquid supply tank, andbecause of this factthe chamber is prevented from filling up with liquid to destroy its usefulness as a relief medium. lVhen pumping ceases, there is always room in the chamber for liquid to enter and thereby relieve the pressure in the system.

Other objects will appear as the detailed description proceeds and will pointed out.

in the appended claims. 1

The invention will-be disclosed with reference to the accompanying drawing in which:

Fig. 1 is an elevational view, partly in section, of a liquid dispensing apparatus embodying the invention Fig. 2 is a sectional view of the expansion chamber; v

Fig. 3 is a sectional view taken on the line 3,3 of Fig. 1, showing the relief-valve controlled by-pass around the pump; and

Fig. 4: is a fragmentary'sectional vie'w of the hose nozzle, showing its valve.

Referring to the. drawing ;the gasoline storage tank, usually located underground, is shown in partat 5(Fig.1) Leading from this tank is the usual suction pipe 6, which extends to the inlet side of a suitablevalve. For the present purposes, the only essential is that there be acheck valve somewhere in the suction pipe and the particular location of the valve is not of essential importance.

The dispensing apparatus shown is illustrative of a common type of meter-pump.

It includes, in addition to the pump 7, a delivery conduit 15 which usually includes, as

. a part thereof, a flexible hose 16 terminat the motor, pump and meter as indicated.

ing with a valved hose nozzle 17. lnterposed in conduit 15 is a suitable meter 18, the indications of which are manifested by an indicator hand 19 read with reference to a dial 20. The nozzle 17 has a valve 21 (Fig. 4), normall held closed by a spring 22 but capable 0 being manually opened by a. lever 23. A support for the nozzle 17, when not in use, is shown at 24 and, adjacent thereto a lever 25 which may operate a switch (not shown) to control the electric motor 26 that drives pump 7. The mechanism described is usually encased, except for the hose, support 24 and lever 25, by a casing 27, which encloses the space between a base 28 and cap 29. These parts 28 and 29 are interconnected by pipe columns 30, which serve to support It is common, in meter dispensing systems of the general character described, to provide a relief-valve controlled by-pass v into chamber 40 a short distance.

around pump 7 to prevent the building-up of dangerous pressures in the system,when the pump is in operation while the nozzle valve 21 is closed. In this particular case, such provisions happen to be built into the pump itself, as will appear from Fig. 3. The suction pipe 6 delivers liquid into a chamber 33 from which it passes through the wall of a filter 34. Liquid leaves through the upper end of the filter, entering a chamber 35 and then passes into the inlet port 36 of the pump. The outlet port of the pump is shown at 37, connected to delivery conduit 15. A valve 38, normally heldclosed by a spring 39, blocks oft communication between the outlet andinlet ports. When suflicient pressure is built up in the outlet, say for example 15 pounds per square inch, valve 38 will open and liquid will be by-passed around the pump.

The feature of this invention is an expansion chamber 40, which is closed except for a single pipe connection 41 extending to the suction side of pump 7. The chamber, as shown, is formed from a short section of pipe 42 of relatively large diameter and two caps 43 and 44 which are threaded on and close the ends of pipe 42 except for the connection 41 with the lower cap 44. The upper cap 43 may have a removable plug 45 to allow 0 ening of the chamber if and when required The connection 41 is preferably of small diameter relatively to the pipes 6 and 15. As shown, it consists of a copper tube having an inside diameter of approximately one eighth of an inch. Tube 41 is connected by a union 46 to the lower end of a nipple 47, which is secured to cap 44 and the upper end .of which extends upwardly Secnred as indicated, to the top of nipple 47 is a more or less bell-shaped hood 48 which extends downwardly in spaced relation with the periphery of the nipple, terminating near but spaced slightly above cap 44. The nipple has an axial passage 49 communicating at one end with tube 41 and at the other with a cross passage 50 extending diametrically through the nipple. The hood 48 serves as a bafile to deflect liquid entering through passage 50 and avoid undue splashing. The chamber 40 is preferably located as high as possiblein the pump casing with the idea of getting it as nearly as possible at the same level as the sight flow indicator 51, which is usually interposed between the pipe 15 and hose 16.

The operation of the device is as follows. Originally, the tube 41 and chamber 40 are filled with air but the first operation of pump 7 will exhaust some of this air and expel it with the gasoline. Since the suction of the pump is applied to tube 41 as well as suction pipe 6, a partial vacuum will be created within the tube and chamber 40. lVhen the desired amount of liquid has been delivered, the hose nozzle valve 21 is closed and then the motor 26 stopped. It is probable that the partial vacuum created in chamber 40 will not long exist but this is not necessary to the success of the invention. If, after the pumping stops, the liquid in the closed system expands under the action of heat, liquid can enter tube 41 and chamber 40, compressing the air therein and relieving the pressure in the system. So also, when the nozzle valve 21 is closed suddenly, rather than gradually, the backward surge of liquid can enter pipe 41 and chamber 40 and relieve the pressure. The sudden closing 0t the nozzle valve arrests the rapidly moving column of liquid and the momentum of this column is expended on the 'nozzle valve. The valve is ushed and the flexible and somewhat elastic ose 16 is pulled out and stretched to some extent by the push imparted to the closed valve and the hose nozzle. Then the hose contracts and there is a backward surge of liquid. It is to be noted that liquid can pass back through the meter 18 and through the pump 7, whether or not the by-pass valve 38 of the pump is open. Butliquid cannot ordinarily pass back through suction pipe 6 into tank 5 because of the closed check valve 8. Therefore, relief for expansion of the liquid in the closed system and relief for the backward surge of liquid caused by a sudden closing of the hose nozzle valve must be provided and the tube 41 and chamber 40 serve this purpose.

- A most important characterist c of the in-' vention is the connection of the expansion chamber to the suction side of the pump as distinguished from the discharge or pressure side thereof. Air domes .have heretofore been connected to the pressure 'side of the fneva'eoo 4 pump but these are'not entirely satisfactory due to their tendency to fill up with liquid. Gasoline will absorb a certain amount of air and the amount which it will absorb varies V directly with the pressure. Therefore, on the pressure side of the pump, air will be absorbed far more rapidly-than on the suction side, resulting in the far more rapid filling up of the expansion chamber with liquid. 1 In-the present case,the depletion of the elastic medium from the expansion chamber 40 is avoided. The gasolineiin it will never be under heavy pressure and at times it will be under a pressure less than atmospheric and will tend to giveup air. .Then again, suction is applied each time the pump is operated, and liquid is drawn fronrthe expansion chamber, if'present there to any substantial degree. .Thus, by the connection of the'ex pansion chamber to the suction side of the pump, the filling up of such chamber with liquid is effectively guarded against'g Another important feature of the inven-' tion relates to its effect in connection with the sight' flow indicator, Heretofore, much trouble has been. experienced by the dropping of the liquid level in the glass'cylinder of the indicator in between operations of the pump. The purchaser expects this cylinder to be full of liquid, and if itis not so,-then his suspicions are aroused. Occasionally some liquid may leak pastthe check valve 8 when it fails to seat properly. A slow leak here in former apparatus of this class will in time cause a drop in level in the indicator. vWith the present arrangement, the. liquid leakage would be replaced by liquid from tube 41 and chamber 40, the air in-thel latter expanding to force the liquid down. This also tends to hold the liquid at the top of the glass cylinder of the sight flow indicator as does also the column of liquid in tube 41 which to some extent at least balances the column of liquid in pipe 15. Thepipes41 and 15, in efiect, w form. the two legs of a U-tube and this'arrangement helps materially in. preventing dropping of the level. in the sight flow indicator as has heretofore occurred.

The invention been disclosed herein, in an embodiment at present preferred for illustrative purposes, but the scopeof the invention is defined by the appended claims rathe than by the foregoing description. p What I vclaim is:

1. In a liquid dispensing apparatus, a storage tank for li uid, pumping means for withdrawing liqui from the tank, a suction pipe connecting the pump and tank, a check valve insaid pipe preventing return flow of the liquid drawn y said means,.'a delivery conduit, a normally closed valve controlling the outlet of said conduit, and an expansion chamber connected to the suction side of said pum ing'means.

at e. aliquiddispensing apparatuaastor age tank for li uid, pumping means for withdrawingliqui from the tank, a suction pipe connecting the pump and tank, a check valve in said pipe preventing return flow of the liquid drawn by said means, a delivery conduit, a normally closed valve controlling theoutlet of said conduit, an expansion chamber, and a conduit of relatively. small cross sectional areaas compared to said pipe and conduit for connecting said chamber to the suc: tion side of the pumping mgans.

3. In a'liquid dispensing apparatus, a storage tank for liquid, pumping means for withdrawing liquid from the tank, a suction pipe connecting the pump and tank, a check valve in said pipe preventing return flow of the liquid drawn by said means, a delivery conduit, a normally closed valve controlling the outlet of said conduit, an expansion chamber having in its lower wall a constantly open Dassage of very small cross sectional area as compared to said pipe and conduit, said chamber being closed except for said passage, and a conduit connecting said passage to the suction sideiof said pumping means.

4. In a liquid dispensing apparatus, a storage tank for liquid, pumping means for with drawing l quid from the tank, a suction pipe connect ng the pump and tank, a check valve in said pipe preventing return flow of the liquid. drawn by said means, a delivery conduit, anormally closed valve controlling the outlet-of .said conduit, an expansion chamber having in its lower wall 'a constantly open passage of very small cross sectional area as compared to-said pipe and conduit,

said chamber being closed except for said passage, said passage opening into said chamer at a point ad acent but spaced from its lower wall, a conduit connecting said passage 1 to the suction side of said pumping means,

and a deflector in said chamber for deflecting liquid entering through said passage toward said lower wall.

- 5. In a liquid dispensing apparatus, a stormy age tank for li uid, pumping means for withdrawing liqui from the tank, a suction pipe connecting the pump and tank, a check valve in said pipe preventing return flow of the liquid drawn by said means, a delivery conit duit extending upwardly from said means to a certain level and then downwardly, a sight flow indicator interposed in said conduit at said level, a normally closed valve controlling the outlet of said conduit, and an expansion chamber connected to the suction side of said pumping means and spaced substantially above the same and closely adj acent said level.

6. In a liquid dispensing apparatus, a storage tank for li uid, pumping means for with- 12 drawing liqui from the tank, a suction pipe connecting the pump and tank, a check valve in said pipe preventing return flow of the liquid drawn by said means, a delivery conduit extending upwardly from said means to 4.

a certain level and then downwardly, a. sight flow indicator interposed in said conduit at said lever, a normally closed valve controlling the outlet of said conduit, an expansion chamber connected to the suction side of said pumping means and spaced substantially above the same and closely adjacent said level, and a conduit connecting said chamber to the suction side of said pump and forming one leg of a U-tube arrangement of which the delivery conduit constitutes the other leg, whereby the column of liquid in the expansion chamber conduit helps to balance the column of liquid in the delivery conduit and to avoid drop in level of the liquid in said indicator.

In testimony whereof I have aflixed my signature.

WARREN H. DE LANCEY. 

